1. Field of the Invention
The present invention relates to an apparatus for automatically adjusting a light axis or lighting area of a light beam emitted from a vehicle headlight in the horizontal direction on the basis of a steered angle of a steering wheel of the vehicle.
2. Description of Related Art
Automatically adjusting a direction of a light axis of a vehicle headlight is known as disclosed in Japanese Patent Application Laid-Open No. 2002-178828.
This document discloses a swivel control technique for horizontally adjusting a direction of a light axis of a headlight of a vehicle, which is characterized in that the adjustment is halted upon detecting that the angular position (steered angle) of the steering wheel of the vehicle and the traveling direction of the vehicle do not accord with each other, or detecting that the vehicle is slipping.
However, the swivel control technique disclosed in this document has a problem in that there occurs unexpected movements in the light axis of the vehicle head light when the vehicle is running on a snowy road, or a gravel road, or a road with wheel ruts, since the steering wheel tends to move in these circumstances despite the intentions of the driver.